Swivel posture chair control



FIG. 1 is a bottom perspective view of a swivel posture chair control showing my new design;

FIG. 2 is a bottom perspective view showing the side opposite that shown in FIG. 1;

FIG. 3 is a top perspective view; and

FIG. 4 is a bottom plan view thereof. 

The ornamental design for a swivel posture chair control, as shown. 